Cold, dark, and oxygen-starved, the depths of glaciers are equivalent to the "sci-fi of cryo-preservation in nature. The ice has entombed — and then returned — numerous objects over the years, ranging in size from dormant bacteria to warplane wreckage.

Here are notable findings from recent decades:

Ancient Anthrax

In August of 106, in a remote part of northern Russia, at least eight people were infected with anthrax after a heatwave melted permafrost and uncovered an infected reindeer carcass in the Siberian tundra. Source

Ötzi the 5,000-year-old Iceman

In September 1991, hikers discovered a frozen corpse in the Ötztal Alps along the Italy-Austria border. The mummified body dated back to around 3300 B.C. Nicknamed Ötzi the Iceman, his body is one of the oldest and most well-preserved in existence: The glacier froze him and the high humidity in the area kept his organs and skin in good condition.

Lyuba the Baby Woolly Mammoth

The month-old woolly mammoth, dubbed Lyuba, was found by reindeer herders in permafrostalong the Yuribey River in Siberia in 2007. Lyuba was incredibly well-preserved thanks in part to a bacteria that colonized her flesh. She may have died after choking on mud after falling into water more than 40,000 years ago. Source

Legendary Everest climber George Mallory

The famed climber disappeared on Mount Everest's peak in 1924 and, 75 years later, mountaineers found his frozen body — complete with name tags and notes on his clothing. George Mallory is believed to have reached the Everest summit nearly 30 years before Tenzing Norgay and Sir Edmund Hillary did, but what became of him during his expedition is still a mystery. Source

A World War II Crew and Their Belongings

In 1941, a British warplane crashed on an Icelandic glacier, killing four servicemen. Pieces of the plane started appearing starting in 1995. In 2000, a pilot's watch was preserved enough that an inscription "From Dad" was still legible, plus a toothbrush and tins of corned beef, were uncovered. In 2004, remains of the crew were finally found. Source

Wreckage from an Alaska Plane Crash that Killed 52

For five decades, an Air Force plane was trapped inside Colony Glacier east of Anchorage after it crashed in 1952. Then in the summer of 2012, the glacier finally gave up wreckage from the doomed flight that killed 52 men. A year later, human remains emerged. At least 31 victims have been recovered so far. Source

Swiss Couple

Just this month, two frozen bodies were uncovered in the Swiss Alps - the bodies of a couple who had gone out to the meadow outside their Swiss home to milk cows 75 years ago — and never came back. Source